文献类型：期刊文献

英文题名：Improving the thermostability of a GH11 xylanase by directed evolution and rational design guided by B-factor analysis

作者：Xing, Hongguan[1,2];Zou, Gen[1];Liu, Chunyan[1];Chai, Shunxing[1];Yan, Xing[1];Li, Xinliang[3];Liu, Rui[3];Yang, Yi[2];Zhou, Zhihua[1]

机构：[1]Chinese Acad Sci, Inst Plant Physiol & Ecol, CAS Ctr Excellence Mol Plant Sci, CAS Key Lab Synthet Biol, Fenglin Rd 300, Shanghai 200032, Peoples R China;[2]East China Univ Sci & Technol, Sch Pharm, Shanghai Key Lab Chem Biol, Meilong Rd 130, Shanghai 200237, Peoples R China;[3]CJ Youtell Shanghai Biotech Co Ltd, Ste 302,Bldg 7,526 Ruiqing Rd, Shanghai 201201, Peoples R China

年份：2021

卷号：143

外文期刊名：ENZYME AND MICROBIAL TECHNOLOGY

收录：;EI(收录号：20205109658820);WOS:【SCI-EXPANDED(收录号:WOS:000702490600003)】；

基金：This work was supported by National Science and Technology Major Project of China (2018YFA0900500), the National Natural Science Foundation of China (31470201; 31741003), Biological Resources Programme, Chinese Academy of Sciences (Grant No. KFJ-BRP-009).

语种：英文

外文关键词：Xylanase; GH 11; Thermostability; Directed evolution; B-factors

摘要：Operational stability under high temperature is required for enzyme application in industrial processes. Error-prone PCR and B-factor analysis were employed to enhance the thermostability of a xylanase from GH family 11 in this study. Based on the top 10 mutants screened from the random mutation libraries, mutant Xyn371 was derived from the optimal mutant Xyn370 by integrating the beneficial residues identified in the other 9 screened mutants. Subsequently, a best-saturation mutant Xyn372 originated from Xyn371 was selected with a 60-min half-life at 70 degrees C (0.5-min half-life for the wild-type enzyme). According to the site-saturated mutagenesis of 10 residues with higher B-factors in Xyn372, mutants Xyn375 and Xyn376 were screened; their half-lives at 70 degrees C were 410 and 360 min, respectively. The substituted residues located in the "palm" region of the N-terminus and the newly generated hydrogen bonds in the mutants might contribute to improved thermostability. The significantly improved thermostability of mutants will pave the way for applications in different industrial areas.